Railway-traffic-controlling apparatus



Fz'g 3 Left Hana Sheet Sept. 6, 1927. 4 41,789

H. A. THOMPSON RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Aug. 6, 1924 7 1o Sheets-Sheet i l\ ga INVENTOR;

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INVENTOR H.-A. THOMPSON RAILWAY TRAFFIC CONTROLLING APPARATUS 10 Sheets-Sheet 4 Filed Aug. 6,1924

fig. 2. v F Rig/n Hand Sheet. G

I W I Q E! I INVENTOR 2 1,641,789 Sept 19 7 A. THOMPSON BAILWAY TRAFFIC CONTROLLING APPARATUS Filed Aug. 6, 1924 l0 Sheets-Sheet 5 .vxg [:5 x x v INVENTOR j H. A; THOMPSON I RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Ant. 6. 1924 10 sheets-sheet; .6

Right Hand Sheet.

INVENTOR:

Left Hanadfzeet Sept.

H. A. THOMPSON RAILWAY TRAFFIC CONTROLLING APPARATUS Fi led Aug. 6, 1924 10 Sheets-Sheet 9 INVENTOR 2 BY Q-a-W ATTORNEY Sept. 6,1927. 1,641,789

- H. A. THOMPSON RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Aue:.6, 1924 1o Sheets-Sheet 10 Rq'qht Hana Sheet.

ATTORNEY Patented 5ept. 5, 1927.

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HOWARD A. TEOIEPSDN, CI? Y'ILleILt SB" 3G, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH 8t SIGNAL COMPANY, G2 S'WifiSVALE, PENNSYLVANIA, ACORP ORATI ON 0F EENNSYLVANIA.

RAILWAY -TRAFFIC-CONTBOLLING' APPARATUS.

Application filed August 6, 192%. Serial No. 730,409..

My invention relates to railway traiiic controlling apparatus.

I will describe two forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 (two sheets) is a diagrammatic view showing a portion of one form of tracltway apparatus embodying my invention. Figs. 2 and 3, each consisting of two sheets, are vie s showing other portions of the apparatus partially illustrated in Fig. 1, and also embodying my invention. Figs. 4 and 5 are diagrammatic views showing portions of a modification of the apparatus shown in Figs. 1, 2 and 3, and also embodying my invention. a

Similar reference characters refer to similar parts in each of the several views.

Referring first to Fig, 1, the reference characters 1 and 1 designate the track rails of a stretch of railway over which traffic normally moves in both directions. This stretch of track is provided with a passing siding X. The stretch of track shown in the drawings is a unit complete in itself, and any number of such units may be placed end to end to form a complete system consistlng of stretches of single track provided with passing sidings. The track rails 1 and 1 are divided, by means of insulated oints 2, into a plurality of successive sections AB, B-G, CD, etc.

Eastbound traffic, that is, trailic moving from left to right, is controlled by, two trackway signals W and 'W located at points D and E, respectively. In similar manner westbound traffic, that is, traflic moving from right to left, is controlled by signals V7" and W located at points E and D, respectively. These signals may be of any suit-able form and are here shown as three-position semaphore signals, each capable of displaying a stop, acaution, or a proceed indication.

Each track section is provided with two track transformers designated by the reference character T with suitable distinguishing exponents and having their secondary windings 3 connected across the rails adjacent the left hand end, and right hand end, respectively, of the associated section.

An impedance 5 is interposed between the secondary 3 of each track transformer T and one rail 1 of the corresponding section in the customary manner. Each section is also provided with two track relavs one located at each end of the section and designated by the reference character It with an' exponent corresponding to the v location. Associated with each trackrelay R is a line trolled in part by stick relays S andS respectively. A similar repeater relay K controlled by stick relay S is locatedat point E. I

Referring now to Fig. 2, each signal V7 is controlled by the associated linerelay H. The line relays for controlling these signals are each of the three-position type and each comprises two windings 7 andS. Referring particularly to relay H associated with signal V one winding 8 of this relay is constantly connected with the terminals a and Z) of a suitable source of alternating currentnot shown in the drawing. It will thus be plain that contact members 9 and '10 of this relay are responsive to the relative polarity of the alternating current supplied to winding 7 of relay H Each of the signals W is provided with a proceed circuit and a caution circuit. When winding 7 of relay H is supplied with alternating current of one relative polarity, which I shall term non mal relative polarity, contact members 9 and 10 are swung to the left and a circuit is closed from secondary winding 11 of trans-. former U through wires 12, 13 and 1%, normal contact 10 of line relay H wire 15, winding of repeater relay P and wires 16, 17 and 18, back to secondary 11 of transformer U The primary 29 of transformer U is constantly supplied with alternating current from some suitable source, such as a generator N over line wires 6 and 6. lVhen this circuit is closed, therefore, relay P is energized and closes its front contacts. As a result a circuit is closed over which cur rent flows from secondary 19 of transformer 20, through wires 21 and 22, front contact 23 of relay P wire 24, normal contact 9 of line relay H wire 25, operating mechanism of signal V and wires 26 and 27, back to secondary 19 of transformer 20. The primary 28 of transformer 20 is constantly connected with secondary 11 of transformer U \Vhen the circuit just traced is closed signal W' displays a proceed indication. When relay H is energized in the reverse direction repeater relay P is energized as before except that the circuit for this relay now passes from wire 14, through reverse point of contact 10 of relay H to wire 15 instead of through normal point of contact 10. The caution circuit for signal V7 is now closed and current flows from secondary 19 of transformer 20, through wires 21 and 22, front contact 23 of repeater relay P wire 24, reverse contact 9 of line relay H wire 30, operating mechanism of signal IV and wires 26 and 27, back to secondary 19 of transformer 20, and the signal therefore displays a caution indication. If the supply of energy to either winding 7 or 8 of relay H is interrupted, contact members 9 and .10 assume intermediate positions, thus breaking both the caution and proceed circuits of signal V at contact 9, and also causing the de-energization of relay P and therefore breaking the circuits for signal W' at front contact 23 thereon. Under these conditions signal displays a stop indication. The control of each of the remaining signals will be readily understood from the foregoing.

Winding 7 of relay H is at times supplied with alternating current by transformer 32, the primary 33 of which is constantly supplied with alternating current from a line transformer U similar to transformer U One circuit passes from secondary 31 of transformer 32, through wire 34, front contact 36 of line relay H wires 37 and 38, front contact 39 of stick relay S, wire 41, front contact 42 of track relay wire 43, winding 7 of relay H wires 44, 17 and 44, front contact 45 of relay H and wir 46, back to secondary 31 of transformer 32. This circuit isclosed only when relays H,

S and R are energized, under which conditions winding 7 of relay H is supplied with alternating current of normal relative, polarity and relay H is therefore energized in the normal direction. Another circuit may be traced from secondary 31 of transformer 32, through wires 34 and 47, back contact 45 of relay H, wires 44, 17 and'44, winding 7 of relay H wire 43, front contact 42 of relay R wire 41, front contact 39 of relay S associated track relays.

wires 38 and 37, back contact 36 of-relay H and wire 46 back to secondary 31 of trans former 32. This circuit is closed only when relays R and S are energized and relay fl is de-energized, under which conditions relay H is energized in the reverse direction. Each of the circuits just traced is provided with a branch passing from wire 37 through wire 48, front contact 49 of an auxiliary relay M back to wire 41. The circuit is closed through this branch only when relay M is energized, under which conditions relay S is removed from the control of relay H The control of relay H will be readily understood from the foregoing. Winding 7 of relay H is provided with a circuit which passes from secondary 50 of transformer 51 (the primary 52 of which is constantly supplied with alternating current from secondary 11 of transformer U through wire 53, front contact 54 of relay P wire 55, front contact 56 of relay R wire 57, front contact 58 of relay R wire 59, front contact 60 of relay R wire 61, winding 7 of relay H wires 62 and 63, front contact 64 of relay P and wire 65 back to secondary 59 of transformer 51. This circuit is closed only when relays P R R and R are energized, under which conditions relay H is energized in the normal direction. \Vhen relays R", R and B are all energized but relay P is de-energized, the circuit for winding 7 of relay H is the same as that just traced except that the contacts 54 and 64 of relay P? are reversed thus reversing the relative polarity of the current supplied to relay H and hence relay H is energized in the reverse direction. The control of relay H is similar to the control of relay H Relays H and H are single element relays and are each controlled solely by the For example the circuit for relay H passes from secondary 11 of transformer U through wire 66, front contact 67 of relay R wire 68, winding of relay I and wires 69, 70 and 71 back to secondary 11 of transformer U his cir cuit is closed, and hence relay H is energized, only when relay R is energized.

Each of the remaining line relays H is controlled by the corresponding line relay of an adjacent section and by the stick relays associated with such corresponding line relay. For example, relay H is provided with a circuit which passes from secondary 11 of transformer U through wire 72, front con tact 75 of relay H wire 76, front contact 77 of track relay R wire 78, winding of relay H, and wires 69, 70 and 79, back to secondary 11 of transformer U This circuit is closed, and relay fl is energized, only when relays H and R are energized. This circuit is, however, provided with a branch which passes from wire 72, through wire 7 3,

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front contact of relay S, and wire 80 to wire 7 6. It will thus be clear that when relay S is ener ized relay H is removed from the control of relay H.

Referring again to Fig. 1, relay S is provided with a pickup circuit and a-stick circuit. Thepickup circuit for this relay passes from terminal a of a suitable source of energy not shown in the drawing, through back contact 81 of track relay R wires 82 and 83, front contact Beef repeater relay P wires 85 and 86, winding of relay S and back to terminal 6 of the energy source. The stick circuit for this relay passes from the terminal a through back contact 81 of track relay t wire 82, back contact 87 of relay S, wire 88, front contact 89 of relay S and wires 85 and 86, through the winding of relay S to terminal 6. Stick relays S S and S are each controlled over circuits similar to those just traced for relay S Stick relay S is provided with a pickup circuit which passes from terminal a, through front contact 90 of relay 5, through wire 91, back contact 92 of relay '8, wire 93, winding of relay S to terminal I). The stick circuit for this relay passes from terminal a through back contact 94: of track relay R through wire 95, back contact 96 of relay 3, wires 97 and 131, front contact 98 of relay S, and wires 99 and 93, through the winding of relay S to negative terminal 6. The pickup circuit for relay S is therefore closed only when relay S is energized and relay S is de energized, thus energizing relay S. The closing of front contact 98 of relay S when relays S and E are both (lo-energized, however, closes the stick circuit for relay 3.

The control of each remaining stick relay S is similar to the control of relay S Repeater relay K is controlled by stick relay S over a circuit which passes from terminal a through front contact 100 of 1-slay S wire 101, backcontact 102 of relay S wire 103, winding of relay K and back to terminal Relay K is therefore energized only when stick relay S is energized and relay S is de energized. The control of repeater relay K by stick relay S is similar to the control of relay K by stick relay 8.

Repeater relay K is provided with a circuit which passes from terminal a, th ough front contact 10% of relay S, wire 105, back contact 106 of relay it wire 107, back contact 108 of relay It w1re 109, wind ng of relay ii and back to ten nnal F);

Directionalrelay M located at point C is provided with a circuit which passes from terminal a, through front contact 201 of an auxiliary relay L located at point l wire 219, front contact 119 of relay S wire 118, front contact 117 of relay K wire 220, back contact 114 of relay K wire 113, back contact" 112 of relay S i'wire 221, winding of relay M and back to terminal 6. This circuit is closed, and hence relay M is energized, only when relays L, S and K are energized and relays K and S are deenergized. An auxiliary circuit is provided for relay M in which current flows from terminal a, through front contact 208 of relay S and wire 222 to wire 220, and thence as before through relay M to terminal Z); it therefore follows that the energization of relay S removes relays L, S and K from the control of relay M The control of directional relay MP at point F will be readily understood from the foregoing.

The auxiliary stick relay L located at point F is provided with apickup circuit over which current flows from terminal a, through back contact 123 of relay H wire 12%, back contact 125 of relay R, wire 126, back contact 127 of relay R wire 128, front contact 129 of relay H wire 130, winding of relay L and back to terminal 6; This circuit is closed, and hence relay L is energized, only when relays H, R and R are de enorgized and relay H is energized. Vv hen relay L is energized a stick circuit is closed passing from terminal a through back contact 94 of track relay R wire 95, back contact 96 of relay S, wires 97 and 131, front contact 133 of relay L, wires 13 1 and 130, windingof relay L and back to terminal Z). This stick circuit is effective to retain relay L in its energized position only when relays S and R are both deenergiz'ed and relay L is already energized. The control of auxiliary stick relay L loated atpoint C is the same as the control of relay L Auxiliary relay Q, located at point G is provided with a circuit over which current flows from terminal a, through front contact 135 of relays S, wires 136, 137 and 37, back contact 138 of relay S wire 139, winding of relay Q and back to terminal 0. This circuit is closed only when relay v 0 is tie-energized and relay S is energized.

When relay M is energized however, terminal a is connected directly to wire 137 over front contactllO of relay M thereby removing relay S from the control of relay Q Auxiliary relay Q, located at point B is controlled in the time manner as relay 13 v Track relay it is constantly connected across the rails adjacent the right hand end of section DE. An impedance 1 11 is in terposed etween one rail 1 and the relay R for the purpose of protecting the relay from excessive currents when the adjacent track transformer T is energized. Under certain conditions however, namely, when stick relay S is energized, a low resistance path is completed around impedance 14:1, whereby the track relay R is connected directly to the rails of section D-E. This low resistance path may be traced from the left hand terminal of impedance 1&1, through wire 142, front contact 143 of relay S and wire ltt, back to the right hand terminal of impedance 1 11. Track relay R is provided with a circuit which passes from rail 1 of section DE, through wire 145, back contact 1 16 of repeater relay K wire 14:7, winding of relay R fiand wire 1 18 back to rail 1 of section D-E. It will be plain that relay R is connected to the rails of the associated section only when relay K is tie-energized. The control of relays R and R is similar to that of relay R and will be understood without further explanation. Relay R is normally connected with the rails adjacent the right hand end of section 13-0, but is disconnected therefrom when relay S is energized, the circuit for this relay passing from rail 1 of section BC, through Wire 215, back contact 216 of relay S wire 217, winding of relay R and wire 218 back to rail 1 of section B-C. Relay R is provided with a circuit similar to that just traced for relay R The remaining track relays R are all normally disconnected from their associated sections but are arranged to be at times con nected across the rails of such sections by the associated stick relay S. For example, the circuit for relay B may be traced from rail 1 of section C D, through wire 1 19, front contact 150 of stick relay S wire 151, winding of relay R and wire 152, to rail 1 of section C-D.

It will be apparent from the drawing that when relay S is de-energized, the secondary at of track transformer T is supplied with energy. The track transformer T located at the other end of section DE is, however, supplied with energy only when relay K is energized. Relay K is energized only when relay S is energized, and therefore only one of the track transformers for section D-E is energized at a time. Furthermore, when track circuit current is being supplied to section DE by transformer T relay R is connected across the rails of the section, and the low resistance path around impedance 141 is open. On the other hand, when transformer T is supplying energy to section DE, relay R is disconnected from the section, and impedance 141 is short-circuited, thus connecting relay R directly with the rails,

Transformer T is energized over front contact 140 of relay M or over front contact 135 of relay S", so that section E-F is supplied with track circuit current from transformer T when either relay M or S is energized. The supply of energy to primary & of track transformer T is controlled by front contact 153 of relay K and hence this transformer is energized only when relay K is picked up. The supply of track circuit current to section CD is controlled in the same manner as just described in connection with section E-JF.

Transformer T located at the right hand end of section F-G is arranged to be energized only when relay S or relay Q is energized, and transformer T tis similarly controlled by relays S and Q Each of the remaining track transformers is controlled by an adjacent stick relay S. For example the circuit for transformer T passes from terminal a, through front contact 15 1- of stick relay S wire 155, primary winding 1 of transformer T and back to terminal 6. It will be seen that the control of track transformers and track relays is such that for each section except section DE, when a track transformer at one end of a section is energized, the adjacent track relay is disconnected from the rails but the track relay at the opposite end of the section is connected with the rails.

Means are also provided as shown in Fig. 3 for supplying to the rails of each section in parallel a current which I will term a local current. For this purpose each section is provided with an impedance a connected across the rails adjacent the left hand end of the section, a similar impedance 0 connected across the rails adjacent the righthand end of the section, and two other similar impedances Z) and (Z connected across the rails at intermediate points in the section. This local current is supplied by local transformers of which one is located at the junction of each two adjacent sections and designated by the reference character V with an exponent corresponding to the 10- cation. The primary winding of eaolr transformer V is constantly supplied with alternating current from the line wires 6 and 6, shown in Fig. 2. For eastbound traffic section DE is provided with a local circuit which passes from secondary 156 of transformer V through wire 157, front contact 158 of repeater relay P wires 159 and 160 to impedance 6 insection D'-E, thence through the rails of the section to impedance 0:, wire 161, front contact 162 of stick relay S wire 163, back contact 164: of relay K wire 165, back contact 166 of stick relay S", wire 167, front contact 168 of relay P and wire 169 back to secondary 156 of transformer V This circuit is closed only when relays P and S are energized and relays S and K are de-energized, under. which conditions local current of normal relative polarity is supplied to the rails of the section D-E throughout their length. If relay P is ole-energized as by the de-energization of relay H due to the presence of a train in section E-F, local current of reverse relative polarity is supplied to that portion of section D-E be tween impedances a and d over the following circuit: From secondary 156 of transformer V through wire 157, back Contact 158 of relay P wire 170, back contact 166 of relay 5 wire 169, back contact 164: of relay K, wire 163, front contact 162 of relay S wire 161, impedance a in section D-E, through the rails of the section to impedance (Z, wire 171, back contact 168 of relay P and wire 157 back to secondary 156 of transformer V It will be seen that section D E is supplied with local current of normal relative polarity throughout its length, or with local current of reverse relative polarity through portion of the section, according as relay P is energized or de-energized, respectively. For governing.

westbound trafiic section DE is also provided with local circuits similar to those just described for governing eastbound traffic as will be clear from the drawing.

Westbound traffic through section EF is controlled by local current supplied to the section over a circuit which passes from secondary 172 of transformer V through wire 17 3, front contact 17 1 of relay P", wire 175, normal contact 202 of line relay H wires 176 and 177, impedance a in section E-F, through the rails of this section to impedance 6, wire 17 8, front contact 17 9 of relay .8, wire 180, front contact 181 of relay K wire 182, back contact 183 of relay S wires 18d and 185, normal contact 186 of rc- H, wire 187. front contact 188, of relay P and wire 189 back to secondary 172 of transformer V Another local circuit may be traced from secondary 172 of transformer V through wire 173, front contact17l of relay P wire 175, reverse contact 202 of relay H wire 18 1, back contact 183 of relay S wire 182. front contact 181 of relay wire 180, front contact 17 9 of relay S wire 178, impedance 6 in section EF, through the rails of the section to impedance a, wires 177 and 190, reverse contact 186 of relay H wire 187. front contact 188 of relay P?, and wire 189, back to secondary 172 of transformer V It follows that when relays S, K and P are energized and re ay S is de-energized, section EF is supplied with local current of normal relative polarity or of reverse relative polarity throughout the length of the section, according as relay H is energized in the normal or reverse direction. If relay H is de-energized. as by the presence of a train in section D-E, relay P is also de-energized and a local circuit is closed over which current fiows from secondary 172 of transformer V through wire 173, back contact 17 1 of relay P wire 191, impedance 5 in section EF, through the rails of the section to impedance 6, wire 17 8, front contact 179 of relay 8, wire 180, front contact 181 of relay I wire 182 back Eastbound traflic through section EF is controlled by local current supplied by transformer V One local circuit may be traced from secondary 156 of transformer V through wire 193, front contact 194 of line relay H wires 195 and 178, impedance 6 in section E'F, through the rails of the section to impedance a, wire 177, back contact 181 of relay 1- wire 180, back contact 179 of relay 8, wire 196, front contact 197 of relay S wire 198, front contact 199 of relay H and wire 200, back to secondary 156 of transformer V This circuit is closed only when relays H and'S are energized and relays S and K are ole-energized, under which conditions section EF is supplied with local current of normal relative polarity throughout its length. If, however. relay H is ole-energized, as by the presence of a train in section F G, a local circuit is closed over which current flows from sec ondary 156 of transformer V through wire 1.93, back contact 194; of relay H wire 198, frontcontact 197 of relay 3", wire'196, back contact 17 9 of'relay 8, wire 180, back contact 181 of relay K fl wire 177, impedance a in section E-F', through the rails of the section to impedance d, wire 201, back contact- 199 of relay H and wire 200 back to secondary 156 of transformer V. i When this circuit is closed local current of reverse relative polarity is supplied to the rails of section E eF between impedances a and d. The local circuits for section CD are exactly the same as for section E-F and will be readily understood without further explanation.

Eastbound and westbound traflic through each; of the remaining sections is controlled by local circuits similar to the local circuits for controlling eastbound traffic through sec tion EF.

Before explaining the operation of the apparatus as a whole it should be pointed out that the trackway apparatus herein shown and described is suitable for eo-operation with train carried governing means in the following manner: When a train occupies a portion of track which is being supplied with track circuit current and with local. current of normal relative polarity aproceed indication is received on board the train;

when the stretch of track occupied by a train is supplied with track circuit current and with local. current of reverse relative polarity.a caution indication is received on the train; but when the supply of either track circuit current or local current to the E-F between impedances I the indications are transferred to the train 'ments. each series are progressively energ1zed,-thatthrough the medium of suitable pickup apparatus, the portion of the apparatus which picks up the track circuit current being located in advance of the forward axle of the train. It is obvious that with apparatus constructed in this manner the supply of track circuit current must always be con nected across the rails in advance of the train, otherwise the track circuit current will be shunted away from the pickup apparatus and the train will always receive a stop in dication.

The trackway apparatus shown in the drawings is arranged to permit movements of-traftic in both directions, the route being set up in one direction or the other through the single track stretches intervening the passing sidings by suitable control of the' stick relays associated with such single track stretches. For example, to prepare the stretch of track to the right of passing siding X for Westbound traffic moves, relays S S S etc. are energized. Since the pickup ner to permit eastbound traflic moves through this stretch of track, stick relays S, S, S etc, are energized. Since the pickup circuit for each stick relay S is carried over a back contact of the opposing stick relay at the same location it is impossible for the route to be set up for conflicting move- Furthermore, the stick relays in is, when relay S is energized, the closing of the front contact 92 thereon completes the pickup circuit for relay S. The closing of relay S in turn picks up relay S and so on, as far as the next passing siding.

As shown in the drawings all parts of the apparatus are in the positions corresponding to an unoccupied condition of the track. Under these conditions all of the track transformers -except transformer T are de-energized. Current is supplied to transformer T over back contact 10a of stick relay S, which is de-energized. Repeater relay K is also de-energized and track relays R and R are both connected with the rails of section DE and both are energized. All line relays H and all the remaining track relays R, all stick relays S, and all repeater relays and auxiliary relays are de-energized. Signals W at passing siding X are all at stop.

In explaining the operation of the apparatus, I will assume that stick relay S and consequently stick relays S and S, are energized due to a westbound train approaching point J. These relays will remain in their energized condition, each being held and hence relay closed by its pickup circuit over a front contact of the corresponding relay for the adjacent section on the right. The closing of stick relay S connects relay R with the rails of section GJ and energizes transformer T The closing of relay S energizes track transformer T and connects relay R with the rails of section FG, and the closing of relay S energizes transformer T and connects relay R with the rails of section EF. The closing of front contact 100 of relay S also energizes relay K which then connects primary l of track transformer T with a source of energy. Relays R R and R are therefore all energized. Relays H H and H are also energized. Each section EF, F-G and GJ is therefore supplied with track circuit current from a source located at the left hand end of the section, and sections F-G and GJ are also supplied with local current of normal relative polarity. If, now, the westbound train enters section GJ, relay R is de-energized, thus de-energizing relay 1-1. As a result the stick circuit for relay S is now closed over back contact 203 of track relay R and stick relay S therefore remains in its energized condition. The train receives a proceed indication throughout the section. The operation of the apparatus as the train passes through section FG will be readily understood. As the trainmoves out of section G J, however, track relay 1 15 picks up, thus breakingthe stick circuit for relay S The pickup circuit for this relay was broken by the de-energization of the stick relay (not shown) for the section next to the right S becomes tie-energized, thereby disconnecting transformer T from its energy source and track relay R from the rails. As the train enters section EF, the de-energization of relay R closes, at back contact 127, the pickup circuit for relay L brief interval before it is again opened at front contact 129 of relay 11 Before this circuit is broken however, front contact 138 of relay L closes and completes the stick circuit for this relay. Relay L therefore remains in its energized condition until the train clears section E l The closing of front contact 204 of relay L completes the circuit for relay M located at point C and this relay therefore picks up. The closing of front contact 205 of relay 1V in turn energizes transformer T and relay Q and relay Q closes the primary circuit for trans former T Relays R and R therefore becomes energized. At the same time the closing of contact 206 of relay Q energizes line relay The closing of the front contacts of this line relay H causes line relay H to be energized in the normal direction over a front contact on relay M and a front contact on relay R The closing of This circuit is only closed for a the normal contacts on relayI-I energizes repeater relay P Signal therefore indicates proceed and local current of normal relative polarity is supplied to the rails of section DE throughout their length.

Under these conditions transformer T is energized over a back contact of relay S", and relays R and R are both connected with the rails of the section and are both energized. The energization of relays P and H therefore causes relay H to be energlzed in the normal direction. Relay P is therefore energized, signal moves to proceed position, and local current of normal relative polarity is supplied to the rails of section E-F throughout their length.

As the train enters section DE relays R and R are de-energized. The de-energization of relay R causes the de-energization of relay H and hence of relay 1, and so allows signal W to display the stop indication. Before relay P becomes de-energized, however, the pickup circuit for relay S is closed and this relay S subsequently re mains closed due to its stick circuit including a back contact on relay R". The energization of relay S completes the circuit for re lay K over back contact 106 of relay R and back contact 108 of relay R "When relay K picks up relay, R is disconnected from section D--E, and transformer T is energized, and track circuit current is there fore supplied to section DE from a point in advance of the train. The train therefore receives a proceed indication as it moves through section DE.

As the train successively clears sections FG and -EF, the apparatus associated with these sections functions as explained in connection with section GJ, relay K at point E becoming de-energized when relay S becomes de-energized.

As the train enters section CD, the deenergization of track relay R completes the pickup circuit for relay S7. This circuit passes over a front contact of relay P which becomes de-energized due to the de-en-ergiz-ation of relay H, but the stick circuit for relay S is closed over its own front contact and the stick relay therefore remains in its energized condition as long as the train occupies section CD. The de-energization of relay H also causes signal VF to indicate stop. The closing of front contact 20'? on stick relay S picks up relay S which in turn picks up S thus picking up progressively each of the relays in this series as far as the next passing siding. It should also be pointed out that as the train moves out of section E-F, thereby causing the de-energization of relay I the original pickup circuit for relay M is opened but this relay is energized, as long as the train occupies section D,E, over a circuit including front contact 208 of stick relay S 'When the train clears section EF, relay M becomes ale-energized, thus opening one circuit for transformer T and relay Q, at contact 205 thereon, but energy is supplied to these devices over front contact 2090f relay S which relay is now energized;

lVhe-n the train clears section DE, re-v and signal W still displays a stop indi-v cation.

.ll1e operation of the apparatus as the train proceeds through sections BC- and A-B will be readily understood from the description of the operation of the apparatus for section G-J. Attention should however, be

called to the fact that when the train clears section B-G, relay S becomes Clo-energized thus de-energizing relay Q but under these conditions transformer T is energized over front contact 210 of relay S 7 The operation of the apparatus for trafiic from left to right is similar to that just eX- plained for west-bound 'movements except that when the train enters section DE the track transformer located at the forward end of the sectio that is, transformer T is al ready energized and hence no change occurs 1n the connections of the track relays and track transformers as the train traverses this section.

It will be seen from the foregoing that if a train is proceeding along the stretch of trackshown in the drawing, and the supply of power to the trackway apparatus is for any reason interrupted, the train will continuously receive a stop indication irrespecive of traffic conditions when the power supply is resumed. To enable the engineman to receive proper indications, certainv manually operable circuit controllers are located at intervals along the roadside for energizing the stick relay next in advance. -For example, I will assume that westbound train is in section F-G and the power fails. When the power is resumed,however, stick relay S will not become energized, but by closing circuit controller 211 at point F, relay S picks up, thus energizing relay K and restoring the apparatus to normal. Similar circuit controllers 212 for movements from left to right are also located at intervals along the trackway.

In connection with the local circuits, I will assume that a westbound train moves into section F-Gr and stops. Relay H is therefore deenergized, and section GJ is lllll supplied with local current of reverse relative polarity between impedances b and e and with no local current between impedances a and Z). The section is also supplied xvith track circuit current from transformer T If, now, a following train enters the stretch of track to the right of siding X,

'it will receive a proceed indication as far as point J, acaution indication between point J and impedance 6 in section GJ, and a stop indication, due to the absence of local current, if the train proceeds past impedance Z). If the train enters section F-G, it. will continue to receive a stop indication since the track circuit current in this section is shunted by the first train already occupying this section.

The protection of following trains proceeding through the other sections will be readily understood from the drawings, the

circuits varying only in details for different sections.

I will next assume that an east-bound train is approaching the passing siding X 1 as in section AB. Relays S and M will therefore both be de-energizcd and relay will be energized. if, now, a westbound train approaches passing siding X such westbound train Wlll receive a proceed indication as far as point F. As the train passes but with no local current between impedances a and b. The westbound train will therefore receive a caution indication between point F and impedance 5 in section DE, and will receive a stop indication if the train proceeds past such impedance Z).

Operation of the apparatus for eastbound traflic is the same as that just described for westbound traffic.

It should be particularly pointed out that all track circuits except the track circuit located at passing sidings' are normally deenergized, are energized only whena train approaches, and are again de-energized as soon as the train clears the first track circuit in advance. The signals are also normally at danger and display less restrictive indications only when a train approaches the signal in the direction in which the signal governs, and then only when traffic conditions are safe. 7

Referring now to Figs. 4: and 5, I have here shown a modification of my invention applied to a stretch of single track provided with a passing siding in similar to that shown in-Figs. 1, 2 and 3. Sections C'D, DE, E-F and are shown complete in these figures, it being understood that additional sections of single track letween passing sidings would be provided, at the junction of each two adjacent sections, with apparatus similar to that illustrated at location G. The primary of each track transformer is constantly supplied with alternating current from secondary 11 of the associated line transformer U, the primary 29 of each line transformer U being supplied as before with alternating current from generator N.

Having reference particularly to Fig. 4, it will be seen that each track section is provided with a track circuit comprising the secondary 3 of a track transformer T and a track relay R. For each section except section C l) the transformer is connected across the left hand end of the section and the relay across the right hand end of the section. in section C-l), however, the relay It is connected across the left hand end of the section and transformer l is connected across the right hand end of the section. Sections CD, D-E and EF are each further provided with asecond track relay connected across the rails adjacent the associated track transformer and are designated R with suitable distinguishing eX- ponents.

Located at point F is a repeater relay O arranged to be energized when relay R is energized. The circuit for relay O may be traced from the left hand terminal of sec ondary 11 of transformer U through wires 219 and 220, front contact 221 of relay R wire 222, winding of relay and wire 224, back to the midpoint of secondary 11 of transformer U A. repeater relay O located at point G is similarly con-- trolled by a track relay (not shown) for the section to the right of point G. Two line relays H and H are located adjacent point D and two similar relays H and H are located adjacent point E. A similar line relay designated by the reference character H with a suitable distinguishing exponent is located at each of the points F, G and 0. Each line relay H comprises two windings 7 and 8 andis similar to certainline relays H illustrated on Fig. 2. Associated with each line relay H is a repeater relay desig nated by the reference character P with the same nponent as the associated line relay.

Located at point E is a directional relay S having a pick up circuit and stick circuit. lVhen relays P R, R and S are de-energized and relay P is energized, a pick up circuit is closed for relay R over which current flows from the right hand terminal of secondary ll of transformer U through wires 225 and 226, back contact 227 of relay lit) lon

P wire 228, back contact 229 of relay 3", wire 230, back contact 231 of relay R wire 232, front contact 233 of relay P wires 23% and 235, winding of relay S wire 236, back contact of a second directional relay S and wires 238 and 239 back to secrelay S in its energized condition when once 7 energized, as long as'relays P5 and S" are ole-energized. I

Located at point Fis a directional relay S comprising two windings 7 and 8 Winding 7 is constantly supplied with alternating current from secondary 11 of the associated track transformer U 'l Vinding 8 of relay S is controlled both by relay S and by a directional relay S located at point F and similar to relay S One circuit for relay S passes from the right hand terminal of secondary 11 of transformer U through wires 225 and 244, front contact 245 of relay S wires 246 and 247, back contact 2-l8 of relay S wires 249 and 250, winding 8 of relay SF, and wires 251 and sorted; to the mid point of secondary 11 of transformer U Then this circuit is, closed,.relay S is supplied with alternating current of such polarity that the, contact fingers operated thereby are swung to the right, which I shall hereinafter term the normal direction? Under this condition the circuit just traced is opened but a branch is closed for this circuit over which current flows from wire 2 17,

through the normal point of contact 332 of relay S and wire 333 to Wire 250. Relay S therefore continues to be energized in the normal direction as long as relay S is energized. When relay S is energized in the normal direction current is supplied to relay S fromfthe right hand terminal of secondary l1 of'transformer U through wires 2?? and 334, normal point of contac ofrelay S wire 336, back point of contact 2 .28 of relay S wires 249 and 250, winding 8 of relay S and wires 251 and 224 back to the mid point of secondary 11 off transformer U When this clrcuit is closed;

the relative polarity of the currents supplied to relay S is such that this relay is energized in the normal direction, and a stick circuit is then closed for relay S- over -which current flows from the righthand terminal of secondary 11 of transformer U through wires 252 and 253, back contact 254 of relay R wire 255, normal point of contact 2&8 o S wires 24:2) and 250,

if and Wires 251 and 224 transformer U It is therefore apparent that relay S having once been energized in the normal direction, will be malntained in this condition as long asrejlay R is deenergized. V V

Relay S Iis controlled by a directional relay iocatctl to the left of'point G and not shown in the drawing in the same manner that relay S is controlled by'relay S Furthermore, a relay S located at-point D is controlled over circuits similar tothos'e of relay S hen this relay is energized, relay S is energized in such direction that the contacttingers thereon are swung to the'left, I shall hereinafter term this the reversed direction of Jenergization. When relay S is energized in the reverse direction relay S is also energized in the reverse direction, and a circuit is clot-Jed for relay S which may he traced from the left hand terminal of secondary 11 vof transformer ,U through wires 219 and 338,- reye'rse point of contact 339 ofrelay S wires 340,241 and'246, back contact 245 of relay S wire 3M, Winding of relay S", and wire224t back tothe mid point;

of secondary 1 1 of transformer U? In a similar manner relay S is arranged to be energized when relay S is de-energized and the first directional relay to the left of'rel'ay,

S is energized in the normal d irection.

It will be plain fromthe foregoing that when relay S is energized the directional relays to the right of point E are succfes sively energized in the normal dir'e'cti'on'as far as the relay locatedat the next'passin'g sidingfto the right and corresponding to re'-' lay S Furthermore, when the'relay lo cated at the next passing siding-to the right and corresponding to relay S is energized, the directional relays '8 associated with the track between such siding and sidin'gIX, (S S etc.) are energized in the reverse direction, and relay S? is also energized.

#I will now'describe the c ont'rol'of the line relays and repeater frelays'. Referring to Fig. 5, one Winding 7, of each line relay loo is constantly supplied with alternating cur- I rent from secondary ll'of an adjacent line transformer U. Relay H is provided with a'circu'itover which current fiows from the left hand terminal of secondary 11 oftrans former QU through wires 262 and1263, front contact of relay P wires 265 and 266} winding 8 of relay-H front contact 267 of relay R", wire 268i front'c'ontact 269 of re-'- lav R ,,w1re*270i front co1itact'27 1 of relay R \vire 272. front contact 273 of relay P and wires 274i {and 275 back }to the right hand terminal of secondary--11 of trans former 'U ,It will be obser ed that conand 264: of relay P" constitute a 'ng'er for controlling "the reatire current suppliedto t acts pole P t are cl ty of 21y Hi? It will bfplaiir relays R, R and R are energized, relay H will be supplied with current'of one relative polarity, which I will term normal relative polarity when relay P is energized, and with current of the other relative polarity, which I will term reverse relative olarity. when relay P is de-enerized, clay I is controlled by relays R R and R and P in the same manner as just described for the control of relay H by relays'l. R R and R Relay H is provided with a circuit over which current flows from the right hand terminal of sec ondary 11 of transformer U through wire 277, front contact 278 of relay O wire 27 9, back point or normal point of contact 280 of relay S wire 281, front contact 282 of relay R wire 283, back contact 284 of relay S", wire 285, front contact 286 of relay R winding 8 of relay H and wire 224 back to the mid point of secondary 11 of transformer U WVhen this circuit is closed, current of normal. relative polarity is supplied verse direction.

. in the reverse position, current is supplied plied to relay H to'relay H If, however, relay O is deenergized, wire 279 is then connected by back contact 278 of relay O with wire 287 and the left hand terminal of secondary 11 of transformer U The current then supis of reverse relative polarit and it follows that contact 27 8 of relay 8 constitutes a pole changer for reversing the relative polarity of the current supplied to relay H The control of relay H" is similar to that just described for relay H except that the relative polarity of the current supplied thereto is controlled by contact 350 of relay R instead of a contact on a repeater relay 0. 0

Relay H is arranged to be controlled by apparatus located at point E or by apparatus located at point G depending on the direction of energization of the associated directional relay S When relay S is ener-- gized in the normal direction one circuit 7 'may be traced for relay H over which current flows from the'right hand terminal of secondary 11 of transformer U through wires 252 and 288, front contact 289 of relay P wire 290, normal point of contact 291 of relay S wire 292, front contact 293 of relay R, wire 294, front contact 295 of relay O wire 296, normal point of contact 297 of relay S wire 298, winding 80f relay H and wire 224, back to the mid point of secondary 11 of transformer U When this circuit is closed. relay H is energized in the normal direction. If however, relay P is tie-energized, the closing of back contact 289 thereon connects wire 290 with the left hand terminal of secondary 11 bymeans of wires 299 and 219, thereby reversing the polarity of the currents supplied to relay H and causing this relay to be energized in thereen relay S is energized .an adjacent line relay H. For

to relay H from the right hand terminal of secondary 11 of transformer U through wires 225 and 300, normal point of contact 301 of relay H wire 302, front contact 303 of relay R wire 304, front contact 305 of relay 8*, wire 306, front contact 307 of re lay R, wire 308, reverse point of contact 297 of relay S wire 298, winding 8 of relay H and wire 224, back to the mid point of winding 11 of transformer U When this circuit is closed the alternating current supplied to relay H is of normal relative po larity. Another circuit is provided for relay H over which current flows from the left hand terminal of secondary 11 of transformer U through wires 239 and-309, re-

verse contact 301 of relay H thence as before through winding 8 of relay H to the mid point of secondary 11 of transformer U When this circuit is closed, relay H is energized in the reverse direction. Still another circuit is provided for supplying current of reverse relative polarity to relay 1-1 This circuit may be traced from the left hand terminal of secondary 11 of transformer U through wires 239 and 310, back contact 311 of repeater relay P wire 312, front contact 313 of relay R wire 304 thence as before through winding 8 of relay H and back to the mid point-of secondary 11 of transformer U The control of relays H and H will be obvious from. the drawing without further explanation. Each repeater relay P is arranged to be energized only when the associated line relay H is energized. For example, the circuit for relay P may be traced from the right hand terminal of secondary through wires 277 and 314, normal or re verse point of contact 315 of relay H wire 316, winding of relay P and wires 317 and 286 back to the left hand terminal of sec- 11 of transformer U for the remaining repeater relays P will be understood without detailed description.

T raffle through each section is controlled by a trackway signal. As here shown each signal is a three position semaphore-signal designated" by the reference character W with a distinguishing exponent, and is located adjacent the entrance end of the associated section for traffic in the direction in which the signal governs. It is understood however that this particular type and loca' tion of signal is not an essential partof my invention. Each signal W is controlled by example, when relay H is energized in the normal direction, current flows. from the left hand terminal of secondary 11 of transformer U through wires 239 and 318, normal point of. contact 319 of relay H wire 320, operating mechanism of signal W and wire 225 back signalthen displays a proceed indicak 

